[sandeep108]

Recently I noticed at an IOC pump that they are now stating fuel density in big LED numbers on the pump. Now density is the basic gauge of fuel adulteration. Of course, the pump guy could rig the display... But anyway, presuming he is on the up and up, what should be the density of the fuels:

1. Normal petrol for metros.
2. Normal petrol for other cities
3. Xtrapremium 91 (there was only a minor density variation from normal petrol).
4. Speed
5. Speed 93
6. Speed 97
7. Power
8. Normal Diesel
9. Turbo/Hi-speed diesel.

I did not have the time to note down the densities displayed, but from now on I will try and keep a note of it every time I fill.

How does the density indicate adulteration?

[tsk1979]

Fuel density will also depend on ambient temp. So it is always better to fill up in the mornings as the fuel has had time to cool down.
As for the numbers
http://www.simetric.co.uk/si_liquids.htm

[rohitbagai]

Well...I know not much ..but hope it helps.
There is as such no standard figures for it. But there is a range that is acceptable acording to BIS standards. For petrol its 710-770 kg/cubic mtr. For diesel its 820-860 kg/cubic mtr....But the criteria is that the petrol/diesel should be kept for 46 Minutes at temp. of 15 Digrees Celcious before test is conducted. Point important here is that for each digree increase will result in increase of 1.2 Lts per 1000 Lts of petrol. So Suppose there is temp. of 20 digree celsius while filling up a 12000 ltrs tanker. When it reaches petrolpump and the temp. at petrol pump is 25 digree celsius the tanker would have extra 72 Lts of petrol in it.
Every time the tanker leaves the depot the invoice it carries states what density was at the time of its departure...Here comes the mafia..The driver already knows what density of petrol he is carrying. The mafia takes out petrol and add other mixtures like pentane, hexane etc. so that the density level maintains.
So In-fact (no offence) it’s the IOC’s useless marketing effort to show transparency.

[sandeep108]

I do feel it is a marketing gimmick - most PSUs/govt. always fudge stuff so real issue is obfuscated. Simple and gradual de-control of entire oil sector will work wonders - but then how will the mafia survive? But isn't most common adulterant for petrol naphtha and for diesel it is kerosene?

[rohitbagai]

Yea they use naphtha kerosene what ever they can. You can check out whole report by centre for science and environment here.
http://www.cseindia.org/html/lab/fuel_alulteration.pdf

[pawan_pullarwar]

Originally Posted by rohitbagai

Well...I know not much ..but hope it helps.
There is as such no standard figures for it. But there is a range that is acceptable acording to BIS standards. For petrol its 710-770 kg/cubic mtr. For diesel its 820-860 kg/cubic mtr....But the criteria is that the petrol/diesel should be kept for 46 Minutes at temp. of 15 Digrees Celcious before test is conducted. Point important here is that for each digree increase will result in increase of 1.2 Lts per 1000 Lts of petrol. So Suppose there is temp. of 20 digree celsius while filling up a 12000 ltrs tanker. When it reaches petrolpump and the temp. at petrol pump is 25 digree celsius the tanker would have extra 72 Lts of petrol in it.
Every time the tanker leaves the depot the invoice it carries states what density was at the time of its departure...Here comes the mafia..The driver already knows what density of petrol he is carrying. The mafia takes out petrol and add other mixtures like pentane, hexane etc. so that the density level maintains.
So In-fact (no offence) it’s the IOC’s useless marketing effort to show transparency.

Nice Info. I was not knowing about density increases in high temp.

[rohitbagai]

Originally Posted by pawan_pullarwar

Nice Info. I was not knowing about density increases in high temp.

Hey.....density decreases when temp. increases. It’s the volume that increases with increase in temp.

[sandeep108]

Anyway, I found out more. At present they check the density in the morning and then input the data into the display! It is really too funny. The supervisor said they are working to make it realtime/automatic but it will still take some time. I did notice the density of extrapremium was higher than that of normal petrol.

[Rehaan]

**----18 months later----**

Originally Posted by sandeep108

...The supervisor said they are working to make it realtime/automatic but it will still take some time....

This has now happened. They are automatically corrected to 15*c

Crosslink : http://www.team-bhp.com/forum/indian...y-display.html

cya
R

[clevermax]

In very new bunks, the machines nowadays indicate the density of fuel as well.

I have noticed that one pump was displaying 786 Kg/m3, and still the "Invalid Density" LED light was glowing. Did anyone notice the difference in density when you fill early in the morning than during mid-day or evening?

Today I filled from another pump in the evening after a hot-sun day and there it was 720 Kg/m3.

[athalaga]

Anyway, I found out more. At present they check the density in the morning and then input the data into the display! It is really too funny. The supervisor said they are working to make it realtime/automatic but it will still take some time. "

The IOC bunk wherein I refill had the same reply.

[Rehaan]

Athalaga,

If the density is corrected to 15*C (as per standard procedure - worldwide), it really doesn't matter at what time the reading was taken!

The purpose of these readouts is to ensure that you are not getting adulterated fuel, and not to ensure that you are getting the most paisa vasool

(On the other hand though - when pumps get fuel from the tankers, they check the density and do NOT temperature correct it -- so they get exactly what they are paying for and not any less!)*

cya
R

* source : the other thread that i've linked to.... or i read it somewhere else on the forum.

[gypsyFreak]

Originally Posted by rohitbagai

Hey.....density decreases when temp. increases. It’s the volume that increases with increase in temp.

If the volume increases with the decrease in density, then isn't there scope for petrol pumps to sell more petrol than they actuall bought.

Consider the following scenarios:
1. As mentioned in post #3, if tanker is delivering 72 ltrs more, then for every 12000 ltrs, the dealer will get 72 * 65 = Rs 4680 profit.
2. What is the dealer is buying the petrol at normal density (720 - 770) and then reducing the density by some means (increasing the temperature), there by increasing the volume and thus selling more than he actually bought.

The customer tends to get lesser density fuel in both cases and thus is not getting what he paid for.

Please correct me if i am wrong...